This application relates to the field of optical mark recognition.
Optical mark recognition (also called optical mark reading and OMR) is the process of capturing human-marked data from document forms such as surveys and tests. Many traditional OMR devices work with a dedicated scanner device that shines a beam of light onto the form paper. The contrasting reflectivity at predetermined positions on a page is then used to detect these marked areas because they reflect less light than the blank areas of the paper.
Many OMR devices use a digital camera. A digital camera is a camera that encodes images and videos digitally and stores them for later reproduction. Specifically, many OMR devices use line-scan cameras, which are a subset of digital cameras. A line-scan camera traditionally has a single row of pixel sensors, instead of a matrix of them. The lines are continuously fed to a computer that joins them to each other and makes an image. This is most commonly done by connecting the camera output to a frame grabber which resides in an expansion slot of an industrial computer. The frame grabber acts to buffer the image and sometimes provide some processing before delivering to the computer software for processing.
While line-scan cameras are functional in OMR devices, there are problems arising from the use of OMR devices. Accordingly, further developments to OMR device and/or to line-scan cameras, or the control thereof, are desired.